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    <title>Document</title>
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<body>
    <script>
        let str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
        let cites = [{
                py: 'beijing',
                name: '北京'
            },
            {
                py: 'alishan',
                name: '阿里山'
            },
            {
                py: 'beidaihe',
                name: '北戴河'
            },
            {
                py: 'shijiazhuang',
                name: '石家庄'
            }
        ];
        let obj = {};
        for(let i = 0; i < str.length; i++){
            obj[str[i]] = [];
        };
        cites.forEach(function(item){
            let i = item.py[0].toUpperCase();
            obj[i].push(item);
        })
        console.log(obj);

    </script>
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